The present invention relates to a powered surgical cutter and more particularly to a sterile disposable powered surgical cutter particularly adapted to perform eye surgery by cutting and removing vitreous from inside the anterior aqueous chamber of the eye.
A history of the development of such cutting devices is described in the AORN Journal, November 1973, Vol. 18, No. 5 page 908 in a article entitled Pars Plana Vitrectomy, a New Treatment for Vitreous Disease.
Eye surgery for management of vitreous in the anterior chamber after cataract extraction or in corneal surgery has been accomplished by several methods. Such methods have included sweeping of the vitreous from a wound with a spatula, aspiration of liquid vitreous through the pupil with a glass syringe and 18 gauge needle, aspiration of vitreous via the pars plana before opening the anterior chamber and removing vitreous directly from the anterior chamber with cellulose sponges and blunt scissors. The problems inherent in such techniques and methods and apparatus are disclosed in the Annals of Ophthalmology, September 1974, page 947 in an article, entitled Anterior Vitrectomy in Cataract Surgery, Aphakic Keratoplasty and Patients with Vitreous Pathology Using a Simple Vitreophage, and in the American Journal of Ophthalmology, June 1974, page 824, in an article entitled Companied Ketratoplasty and Cateract Extraction. In accomplishing eye surgery in the anterior aqueous chamber it has been found that after the incision is made it is sometimes necessary to draw off vitreous or in turn add vitreous fluid. Apparatus for accomplishing these ends is discussed in both of the above-mentioned periodicals. This initial apparatus was developed by Herbert E. Kaufman and incorporated various components and concepts that were well known in the art as is disclosed by the following patent references.
U.S. Pat. No. 3,734,099 discloses a hand held powered surgical cutter utilizing a cutter tip having an outer fixed tubular cutter in which an inner tubular cutter is rotated. The cutter tip is inserted into the eye and the inner cutter is rotated cutting the vitreous. The pieces of the severed vitreous are then removed through the interior of the inner tubular cutter to a disposal means. U.S. Pat. No. 3,618,861 discloses another similar hand held tubular cutting apparatus adapted to cut the vitreous in the eye and suck the cut vitreous to disposal means.
The use of ultrasonic energy in a surgical instrument to cut the vitreous is taught by U.S. Pat. No. 3,805,787. The apparatus has a probe head with bores cut therein to receive both suction means adapted to remove material emulsified by the probe and fluid transfer means to transmit irrigation fluid into the eye.
Another hand held vitreous cutter is disclosed in U.S. Pat. No. 3,732,858 which utilizes a rotating blade mounted in a tube to cut the vitreous material. As the vitreous is cut suction means draws the vitreous material back up through the tube housing of the cutting blade to an area for disposal. The apparatus is also shown in another embodiment adapted to be used with infusion means for submitting or directing fluid into the eye. The present invention represents an improvement over this previously identified prior art.
All of the previously disclosed apparatus must be sterilized after each operation. A common sterilization technique in hospitals is to sterilize the units with ethylene oxide. The construction of the apparatus is such that the cutter blade assembly which is hardest to sterilize, is difficult to reach in sterilizing processes, expensive to manufacture and is constructed to form a complex cutter assembly. Furthermore the drive mechanism of the cutters blade assembly has to be sterilized after each use resulting in damage to the mechanism after repeated sterilization not to mention the time, labor and expense required for each sterilization.
The present invention is thus constructed with a simple disposable cutter assembly which can be either disposed of or sterilized while another cutter assembly is placed on the drive housing. The novel use of a removable protective bag which is sealed by the disposable cutter assembly to the drive housing prevents the drive housing from being contaminated so that the drive housing can be reused within minutes or within a minute after its use in the previous operation. Because of the self contained power source the instrument can be used in the field or in other remote places where power is not available. Thus the invention provides a sophisticated low cost sterile medical instrument available for use under any environment or condition.